Hemadynamometer operating according to the compensation method



P" 1936' H. HESSE HEMADYNAMOMETER OPERATING ACCORDING TO THE COMPENSATION METHOD 3 Sheets-Sheet l rm we yr 3 a 0W M n/ 7. a w m z a flfi 2 P 0 m v w y 2 2 7 W m 2 w 5 7 Z 5 m1 3 a 1 v1 6 32 4 8 mm 2 1 2 v D O0 0) 0 NY 00 T 7 4 WW H. HESSE April 28, 1936.

HEMADYNAMOMETER OPERATING ACCORDING TO THE COMPENSATION METHOD 5 Sheets-Sheet 2 Filed Sept. 7, 1932 inventor g Asse 5y H. HESSE April 28, 1936.

HEMADYNAMOMETER OPERATING ACCORDING, V'I [O THE COMPENSATION METHOD Filed Sept. 7, 1952 3 Sheets-Sheet 3 [72 van for fla ger Hesse 6y Patented Apr. 28, 1936 i w l a v.

HEMADYNAMOMETER OPERATING Ac-f conpmc TO THE COMPENSATION METHOD' Application September 7, 1932, Serial No. 632,076 InGei-many September 15, 1931 as Claims. on. 73-44) I This invention relates to an improved hematively, as the case may be, as long as air shocks dynamometer operating according to the comare produced in the cuff or bandage owing to the pensation method, in which theair pressure is action of-the pulsations, or the oscillations of the increased within a pneumatic arm bandage or pulse respectively, whereby'too high a speed of end until fluctuations of the pressure (observed the air entering said hermetically closed space .5 at a gauge)' are noted which result from the and into the said cuff is prevented, thus, avoiding; pulse beat and the commencement of which is uncertainties orinaccuracies of the measureconsidered to be the lower limit 01E the 'pressure ments. As long as pulsations are produced, that of the blood, the so-called diastolic limit. isto say, a l as. for xa p h maximum 11 On a further increase of the air pressure in the of the blood pressure has not been attained, .the

pneumatic bandage the fluctuations caused by p y Valveremains p fi S p the pulse beat cease, and this ceasing isconsidof the continually supplied air is, therefore, sufliered to constitute the upper limit of the pressure cient. of the blood, viz. the so-called systolic limit which According to this invention, the air shocks pro- 15 up to now has'chiefly been used as basis for duced in the hermetically closed space-can be the measurements in question; v caused to act in such a manner upon the' con- In fiecting measurements according to the trolling device arranged in said space that the compensation method it is customary to consupply of air to the cuff is interrupted either nect the arm-bandage that is' to be placed over by the Commencement by h ceasing 0f the the pper-arm artery with acompressed-air storoscillations of the pulse, whereby it is rendered 20 age receptacle, and to regulate the supply of this p ss ble that the ower; as well. as the upp air to the bandage by means of the oscillations limit of the blood pressure can be measured or of the pulse, in such a manner that a contact re a device operated by the pulse beat is arranged In order to render the device particularly sen- I 5 over the radialis pulse, whereby this contact desitive, there may be provided in the hermetically vice inturn actuatesa valve located in the air closed space a contact device designed in the connection between said compressed-air storage manner of an electric instrument with rotary receptacle and the said -arm-bandage. spools, one arm of this instrument being acted Devices of this type do not only require the on by the air shocks and the other a'rm'serving provision of two separate devices which are to for producing the contacts. 30

be'attach'ed to the arm, but are also not always A hemadynamomete'r operating after the comreliable, because, if the contact device should pensation method and improved according to the be pressed against the .pulse too tight or: too slight present invention is illustrated diagrammatically oris applied otherwise in an incorrect manner, .and by way of example on the accompa the result of the measurement is likely to be drawings, on which Figure'l shows the complete 35 incorrect. r arrangement and combination of parts consti- The principal object of the invention consists tuting the apparatus; Figure 2 is a similar illusin an air-tight space which is connected with a tration' showing a modification; Figure 3 is a pneumaticarm eufi or bandage and in which vertical section through an apparatus corre- 40 is arranged a device controlling the supply of sponding with Fig. 2; Figure 4 is a side-view of 40 the air to the cuff and to said space, said device this apparatus; Figures 5 and 6 show certain being influenced by theair shocks produced in details more fully dealt with hereinafter, and the cufi and being caused by the oscillations of Figure '7 is a.blood pressure diagram which will the pulse, whereby the operation of the appaassist in thoroughly understanding the invents ratus is madeindependent of the absolute height tion. of the-pressure. 4 I Referring to'Fig. 1, l denotesthe pneumatic Another object of the present invention conarm cuff or bandage and 2 is a hose connecting sists in the provision of regulating members by said cuif with a nozzle -3 extending into a herwhich the speed of the air or other gas supplied metically closed chamber 4, in which is sup to or withdrawn from thecufi and the air-tight ported a two-armed lever 5, 6 on an axle 'I in 5o space is so limited that the air shocks which the manner of an electric instrument with rotary the pulse produces are not detrimentally afiected. -Spools. The arm 5 of said lever bears a cap 80 A regulating memlier arranged in the pipe supwhich normally keeps the orifice of th'enozzle plying the air etc. to the cuff and to the hermeti- 3 closed; the arm .6 of the said lever bears 2 cally closed "space is kept open or closed, respeccontact piece 9 which when the lever is turned 00 UNITED STATES PATENT o -"rice? in clock-wise direction pushes upon an adjustable contact screw III extending from the out-. side-into the chamber 4. The lever 5, 6 is held by a spring I I normally in that position in which the cap 8 keeps the nozzle 3 closed.

The chamber 4 is connected by a pipe I2 with a bottle or the like I3 containing compressed air or'any other suitable gas under pressure. I4 is a pressure-reducing valve inserted into said bottle or the like I3. 7

The pipe I2 is partly subdivided into two branches I2 and I2, of which I2 contains an electrically controlled valve I5 and a throttle orifice I6. Another throttle orifice I1 is arranged in the pipe l2 just in front of the chamber 4, and a third throttle orifice I8 is provided in a branch I9 of the pipe I2, this branch connecting the pipe I2 with the body member I9 of the nozzle 3, said latter member establishing the connection between said nozzle and the hose 2.

When the valve I5 provided in the branch I2 0! the pipe I2, as Stated, is opened, air streams from the bottle I3 into the chamber 4, as-well as into the pneumatic cuiI I. The several throttle orifices are so adjusted that the relations between the pressures in the chamber 4 and in the cuff I remain unchanged.

when the pressure in certain height, the oscillations of the pulse commence in known manner, as indicated at I in Fig. '7. The respective height of the pressure is considered to constitute the diastolic limit of the blood pressure. The amplitudes of these oscillations have various values. When the pressure in the'cuff is further rising, owing to the continued supply of air, the oscillations will cease at a certain distinct height of the pressure, as indicated at 11 in Fig. '7. This point is considered to constitute the systolic limit of the blood pressure. I

' Filling the cuff land the chamber 4 up to the lower limit of the blood pressure is effected by opening a valve 20 arranged in the branch, I2 of the pipe I2, at which time the valve I5 re.- main closed. I wish it, however, to be understood that said branch I2 is not indispensably requisite, but may be. dispensed with, in which case the valve I5 must, however, be open so as to permit the rise of the pressure.

Now, in order to make in a given case the state of the blood pressure continuously visible at the indicating and writing manometer 2I that I is connected by tube 2| with the chamber 4, or to attain the same result with the aid of a recording instrument of any suitable known type and also connected to chamber 4, the following arrangement and combination of parts has been devised: I

The contact screw III and a conducting member 22 provided at the outer end of the spring II are located in a circuit serving for controlling a relay 23 acting upon the valve I5. The oscillations of the pulse produce air shocks in the cufl I which then proceed forward and outwardly through the nozzle Sandmove the lever 5, 6. At every oscillation of this lever a contact is established between the contact members 9 and III, and a rush of current passes. through the controlling relay 23 across a highly sensitive anxi liary relay constituted, for instance, by a suitable known electronic tube 24, the air valve I5 being then opened by the action of the relay 23.

3! which is operated and an intermediate relay electron tube 24 and by the anode current of the the cufl has attained a shown more clearly in Fig. 2. The valve 20 is closed at this time. As the opening of the valve I5 is only very short, in that'it has been produced by a rush of current, as stated, and as,

therefore, the amount of air necessary to inheight of pressure in the cufi, the retarding relay 25 would still retain its energization and therefore be efiective in maintaining the circuit closed before thecontact members in the circuit of relay 23 become separated from each other. Only when an impulse has passed by, that is to say, when the point 11 of the diagram (Fig. 7) has actually been attained and no further oscillations of the pulse take place, is the circuit interrupted and the valve I5 closed. By reason of the thus attained continuous supply of air to the cuff I and to the chamber 4 the speed of the air can be kept so low that the air supply cannot afiect detrimentally the result and indication of the measurement in any way.

The throttling members I1 and I8 and the air pipes are arranged and adjusted relatively to one another in such a manner that the supplied air gets solely into the chamber 4 and into the cuff I, but cannot escape through the nozzle 3.

In a branch I2 of the air pipe I2 is provided a throttling member 26 through which air escapes continually into the atmosphere in order to enable the apparatus to follow a decrease of the blood pressure. 4

When the pressure in the cut! I and in the chamber 4 decreases owing to the escape of the air through-the throttling member 26, the oscillat'ions of the pulse arise again and entail opening of the air-supply valve I5. This procedure is continually repeated, and by appropriately adjusting the contact screw II! it is rendered possible to make the point II (indicated in Fig. 7), that'is to say, the point on the gauge corresponding to the upper blood-pressure limit, continually visible at the gauge 2|, or to registenthis presratus (not shown).

In order to interrupt the measurement after a through which extends an iron pin 44 into said tube and is pressed against said hose by a spring sure continually on a suitable recording appa- 44 The pin 44 is, intact, the core of a solenoid, of which the coil 43 forms the other part. When current is flowing through this coil, the pin or core 44 is drawn into the coil and the sectional area of the hose 42 is increased so that a correspondingly large amount of air can flow therethrough. I'wish it, however, to be understood that the piece of tube 4I may be dispensed with if instead thereof an abutment member for 4 the piece of hose just counter to the end or the pin or core is provided, as will be clear without' further details. And I .wish it further to be understood that the air valve in question may be out affecting. the elTect of the same.

Concerning the constructional form shown in Fig. l'and dealt with on the preceding pages it has been assumed that the bandage or cuff I contains an inflatable member which i's connected with the nozzle 3 by the hose 2 and from which escape the rushes of air produced by the oscillationsof the'pulse. In particular cases it may, however, be desirable to withdraw the air not from the damming cufi proper, but from a separate inflatable member which is provided at a certain distance from said damming cufl and is not acted on by impulses arising. outside of said cufi as soon as the pressure in the other cuff has reached the height of the blood pressure. A thus modified cufi l is shown in Fig. 6 in which 52 denotes a pneumatic cushion. that forms the dainming cup proper and with which the'air pipe I9 is connected, whereas 53 is another pneumatic cushion which is connected with the nozzle 3 (Figs. 2

and 3) by means of the hose 2.

Referring now to Figs. 2, 3 and 4, this construc-.

tional form is so designed as to enable the operator to measure the lower andthe upper limit of the'blood pressure. Those reference numeral s which correspond with the same reference Fig. 1.

The filament cathode of the thermionic tube 24 is heated by a battery 45. A current, there- .fore', flows continually from the battery 52 for the anode through the winding of the relay 3|,

which relay thereby maintains the contact 46 in the closed position indicated in Fig. 2. when the switch lever 41 also assumes the position shown in Fig. 2, alternating current will flow then from the source of alternating current indicated at 53 through the levers 46,." and through the winding of the control relay 23 for the valve I5. The" valve l5 thereby is being opened and the air from the receptacle l3 escapes through the conduit l2.

tothe hermetically sealed casing 4, a portion of this air also entering through a branch I! and flexible tube.2 to the arm cuff I. When a certain pressure is thereby produced in the cuff, the

.' oscillations due to'the' pulse beat will be transmitted through the same tube 2 and nozzle 3 to -the lever 5, 6 in the casing 4, this lever being thereby rocked to establish contact between the contact elements 9 and III in the casing. A negative voltage from the battery 56 is thereby placed.

of'the air from the throttling valve 26, the pressure in the cuff I has decreased and the rushes of air from the nozzle 3 have ceased, the contact lever 5, 6 swings back into its former position and :opens the contact I. Now current commences 3 again to flow from out of the electronic tube '24,

and the contact 46 is again closed by means of the relay 3| whereby the air-supply valve I5 is again opened and the phases described are repeated. By an appropriate adjustment of the contact screw 0,.the writingmember of a record- 3 ing instrumentcanbe caused to oscillate so slightly that the line it produces is nearly straight.

In order to ascertain the upper blood pressure limit, or to record the same, the switch lever 41 is turned downwardly soas to contact with the contact 48. Air from the bottle I3 is being led to the hermetically closed chamber 4 and to the cushions 52 and 53 of the cult I through the filling valve 20'or through the valve l5, this airsupply being maintained until the oscillations of the pulse arise again. -The valve 20 is now being closed. As soon as. rushes of air escape from the nozzle 3, the lever 5, 6 thereupon again closes the contact l0. 'Thus, thegrid of the tube 24 is loaded and the current coming continually from the electronic tube 24 across the relay 3| is in-' terrupted, as is, therefore, also the contact 46, and

as now the contact 49 is closed, the current flows tronic tube 24 can again act in the already denumerals in Fig. 1 denote the same parts as in circuit of the control 'rela'y 23 has been inter-' rupted.

When measuring the upper blood pressure limit the writing member of a recording instrument may be caused to oscillate only very slightly and to draw a nearly straight line by suitably adjustingthe contact screw 0.

In order to attain a quiet and continuous su-ppFy of the air to the chamber .4 and to the cushions 52, 53 of the cuiT I in spite of the short duration of the contacts, a delaying system 25 comprising a condenser 50' and a resistance 5| is provided also in connection with the modification in question. This delaying system operates by charging the condenser 50 intermittently upon closure of the contact 9, I in the casing 4. -When this contact is open, asindicated in Figs. 1, 2 or 8, a gradual discharge of the condenser 50 takes place through the high resistance 5|'. Owing to the insertion 'of this high ohmic resistance, the negative grid voltage'of the tube' 24 slowly decreases. It is possible to select a resistance of such values that this voltage on the grid has become low enough only after the expiration of about one second to permit current from' the anode of the tube to flow through the winding This current will then suflice to actuate the contact 46.

By a suitable adjustment of thecontact screw I it is also rendered possible to ascertain the amplitudes of the oscillations produced'by the pulse oscillations, or to trace the greatest thereof.

I wish it to beunderstbod that I do not limit myself merely to the details of the arrangements and combinations of parts shown solely by way of example. Many departures in the detais are possible without constituting departures from the gist of the invention.

I claim:

1. A hemadynamometer operative according to the compensation method, comprising, in'combination, an arm cu'fi and'a hermetically closedchan'iber connected therewith, a pressure gauge in communication with said chamber; means adapted to supply air to said cufi and said chambet, and means responsive to the shock-like varia;

tions of pressure between the cuff and the'chamber caused by oscillations of the pulse, for regulating the air supply to said chamber.

2. A hemadynamometer operative according to the compensation method, comprising, in combination, .an arm cuff and a hermetically closed chamber connected therewith, a pressure gauge 'in' communication with said chamber; means adapted to supply air to said cufi and said chamber, means responsive to the shock-like variations of pressure between the cuff and the chamber caused by oscillations of the pulse for regulating the air supply to said chamber, and means to retard the regulating movements of said regulating device.

3. A hemadynamometer operative according to the compensation method, comprising in combination an arm cufi, a hermetically closed chamber connected with the cufi, a source of fluid pressure, conduits extending from said source to said cufl and to said chamber, a contact device in said chamber, and means under control of said contact device for obstructing one of said conduits from said source upon initiation and upon cessation of pulse oscillations transmitted by the arm -cufi, whereby the pressure conditions in such chamber are varied in dependence upon pulse oscillations and a pressure gauge in communication with said chamber.

4. A hemadynamometer operative according to the compensation method, comprising in combination an arm cufi adapted to respond to pulse oscillations, a hermetically closed chamber connected with the cufi, a source of fluid pressure, conduits extending from said source to said cuff and to said chamber, a contact lever oscillatably supported in said chamber, one arm of said lever being subjected to the flow of air entering through the communicating conduit between the cuff and the chamber, the other end of the lever carrying a contact element, a companion contact element stationary in said chamber, and means under control of'said contact elements for obstructing one of said conduits from said source upon initiation and upon cessation of pulse oscillations transmitted by the cuff, whereby the pressure condi-- tions in said chamber are varied in dependence upon the pulse oscillations and a pressure gauge in communication with said chamber.

5. A hemadynamometer operating according to the compensation method comprising in combination an arm cufi adapted to respond to pulse oscillations, a hermetically closed chamber in communication with the cufi, a source of fluid pressure, conduits extending from said source to said cufi and to said chamber, a two-armed lever pivoted in said chamber, a switch contact piece on one end of the lever, the other end of the lever overlying the end of the'conduit between the arm cuif and the chamber, a companion contact stationed in the chamber whereby a circuit is closed upon oscillation of said lever in response to shocklike variations of pressure in the chamber caused by the pulse oscillations transmitted from the arm cufi, another circuit containing a relay, a valve in the conduit extending from the source of pressure fluid to the arm cufi, said valve being under control of said relay, the circuit containing the relay being controlledby the circuit established upon closure of the said contacts, whereby the pressure conditions in the chamber are varied in dependence uponthe pulse oscillations, and a pressure gauge in communication with said chamshock-like movements of air through the conduits and to regulate the supply of air of higher pressure in different chambers, whereby the pressure increases uniformly in such difierent chambers, a contact device in the chamber, means under control of the contact device for influencing the air throttling members, whereby the pressure conditions in the chamber are varied in dependence upon the pulse oscillations and a pressure gauge incommunication with said chamber.

7. A hemadynamometer comprising an arm cufi", a source of pressure, a hermetically sealed chamber, a nozzle leading into said chamber, a conduit connecting said nozzle and arm cufi, a two armed lever pivoted in said chamber, a cap on one arm of said lever which normally keeps the-orifice of the nozzle closed, a switch contact piece on the other arm of said lever, means providing communication between the source of pressure and said chamber and cuff, an electrically operative valve for controlling said communicating means, an electric circuit for operating said valve, said circuit including a switch contact extending into said chamber for cooperation with the switch contact piece on said arm, whereby the circuit is closed upon oscillation of said lever in response to shock-like variations of pressure in said nozzle caused by the pulse beat for regulating the air supply to said chamber and cuff, and pressure measuring means incommunication with said chamber.

8. A hemadynamometer operative according to the compensation method, comprising in combination an arm cufi adapted to respond to pulse oscillations, a hermetically closed chamber in communication with the cuff, a source of fluid pressure, conduits extending from said source to said cuff and to said chamber, a'contact device in said chamber actuated by intermittent gusts of air flowing from the arm cufi to said chamber and chamber are varied in dependence upon the pulse oscillations, and a pressure gauge in communication with the chamber.

HOLGER HESSE. 

